Various forms of devices for cooling and thereby condensing refrigerants have been known for many years. One of these has been a serpentine cylindrical tube in which a cooling fluid passes transversely across the spaced lengths of the tube, as disclosed in Engalitcheff U.S. Pat. No. 3,146,609, and Doroszlai No. 3,366,172.
Other various arrangements for heat exchange in which attempts have been made to increase the surface available for heat transfer within a given space are illustrated in other patents including Wescott U.S. Pat. Nos. 1,657,704, Stevens 2,051,277, Hemphill 2,060,211, Huet 2,911,199, Raskin 4,002,200, Fitch 4,235,281, and Uehara et al. 4,237,970.
The use of tubes in various shapes for heating or cooling is known in other patents including Aramaki et al. Nos. 3,964,872, Sumitomo et al. 4,314,605, Brown 1,501,646, DuTrembley 6,929, and the French patent to Green 807,796 of 1936.
Closed plate sections have been used in metal radiators as for example in Tellander U.S. Pat. Nos. 1,726,458, Pulsifer 2,926,003, and the Canadian patent to Adams 580,387 of 1959.
Feldmeier 2,057,298 discloses a milk cooler, not an evaporative cooler, having spaced tubes in closed parallel sections, the tiers of which are hinged together.
Schinner U.S. Pat. No. 4,196,157 discloses a coil assembly with tube segments that are spaced apart by more than one tube diameter but not substantially more than two diameters, Schinner stating that the velocity of the air between the tubes varies from 400 feet (122 meters) per minute, but less than 1,400 feet (427 meters) per minute. Schinner attempts to select a velocity at which the downwardly flowing waer is not scrubbed from the tube surfaces. However, in Schinner the water drops downwardly through spaces through which the air flows so that substantial entrainment of liquid with air results.